Similar problems. Randomly some notebooks do not display the notes within them and I get the "Sorry we are having trouble page".
SUPER annoying. I use EN hundreds of times a day and this is driving me up the wall.
Quitting EN does not fix it.
Rebooting Mac does not fix it.
Its pretty random - sometimes a given notebook will work, sometimes not.
All notes work in web view.
All notes work in older (< 10.x) version of EN on a different Mac.
Only started happening on the update to 10.5.7 I think.
v 10.5.7 build 2171 public
Editor: v114.1.14753
Service: v1.25.2
macOS Catalina, 10.15.7